1. Field of the Invention
The present invention relates to a deflector, an optical scanner, and scanning distance measuring equipment, which are used for three-dimensionally scanning measurement light, for example.
2. Description of the related art
Japanese Unexamined Patent Publication No. S60-12527 discloses an infrared beam scanner that includes a gear mechanism supporting a mirror so as to swing about a horizontal axis, and a motor for driving a light emitter/receiver provided at a support shaft to rotate about a vertical axis. The motor is driven to rotate the mirror about the support shaft, the posture of the mirror is changed by the gear mechanism associated with the motor, and a light beam outputted from the light emitter/receiver is reflected by the mirror and scanned three-dimensionally.
Japanese Unexamined Patent Publication No. 2001-50723 discloses a distance measuring device according to the TOF system, including a motor for vertical deflection, supporting a mirror to swing about a horizontal axis, and a motor for horizontal deflection, driving the mirror to rotate about a vertical axis.
Japanese Unexamined Patent Publication No. 2003-287693 discloses a light beam scanning mechanism that includes a motor for rotating, about a vertical axis, a mirror provided with a ferromagnetic body or a permanent magnet and an electromagnet for deflecting the mirror about a horizontal axis.
However, the infrared beam scanner disclosed in Japanese Unexamined Patent Publication No. S60-12527 adopts a mechanical swing mechanism for swinging the mirror about the horizontal axis by means of the gear mechanism. Therefore, the mirror cannot be swung at high speed, and the swing angle thereof cannot be controlled precisely, which lead to poor measurement accuracy. There is another problem that the device fails to be decreased in size.
In the distance measuring device disclosed in Japanese Unexamined Patent Publication No. 2001-50723, the mirror is driven by the motor for vertical deflection. Therefore, the mirror cannot be swung at high speed, and the device fails to be decreased in size.
The distance measuring device disclosed in Japanese Unexamined Patent Publication No. 2003-287693 is driven by the electromagnet, which requires the special mirror provided with the ferromagnetic body or the permanent magnet and increases the cost. Furthermore, the distance measuring device cannot be driven at high speed and fails to be decreased in size.
In each of the devices disclosed in Japanese Unexamined Patent Publications Nos. 2001-50723 and 2003-287693, the mirror rotating about the vertical axis is swung by the motor for rotating about the horizontal axis or the electromagnet. In order to input a driving electrical signal to the motor for rotating about the horizontal axis or the electromagnet, a slider structure for signal transmission needs to be provided to a vertical rotary shaft of the mirror or the like. Therefore, the life of the device is shortened due to mechanical abrasion at portions in contact with each other.